Laminated elastomeric bearing unit

Claim 1

An elastomeric bearing assembly comprising a first member adapted to be operatively coupled to the support shaft of a rotor blade mounted for rotation in conjunction with the hub of a helicopter and forming a first frusto-conical surface, a second member adapted to be coupled to the shaft and forming a second frusto-conical surface spaced from said first surface, a pair of frusto-conical elastomeric bearing sections disposed between said first and second surfaces, one of said frusto-conical bearing sections being bonded to the first surface and the other section being bonded to the second surface, said frusto-conical bearing sections each having a plurality of alternating and bonded frusto-conical layers of elastomeric and non-extensible material and having planar surfaces, an intermediate member separating said first and second frusto-conical bearing sections, said first and second frusto-conical bearing sections being arranged to receive the resultant force vectors from an applied load in a direction normal to the planar surfaces of said layers of elastomeric and non-extensible material, said frusto-conical sections being disposed along an axis normal to said planar surfaces which is at an angle less than 45 degrees to an axis extending parallel to the support shaft of the rotor blade, a spherical bearing section adapted to be coupled to the blade support shaft and mounted in serial relationship to said first and second frusto-conical surfaces, and means forming a centering bearing operatively coupled to at least a portion of said spherical bearing section and in bearing relationship with the support shaft.